In breast cancers and sarcomas, a variant polymorphism in the cell cycle inhibitor P21CIP1/WAF1 is under-represented in those individuals whose tumours contain mutated TP53. The aim of this study was to determine whether this variant polymorphism was also under-represented in those with ovarian carcinoma and TP53 mutations. We studied lymphocyte DNA from 104 women with ovarian carcinoma, 15 with borderline tumours and 16 with benign tumours, using a previously-reported PCR-RFLP technique. 96 of the ovarian carcinoma cases had been previously examined for mutations in TP53 and/or for overexpression of the TP53 protein. The variant allele was seen in 11 out of 104 women (10.6%) with ovarian carcinoma. There was no significant difference in the distribution of the variant allele in the women whose tumours had (7/47) or did not have (4/49) TP53 mutations (P = 0.523). It does not appear that the presence of this variant allele of P21CIP1/WAF1 has any aetiological role in ovarian carcinomas. Studies in other tumours support this finding.